actabiomedicaActa Biomedica ScientificaActa Biomedica Scientifica2541-94202587-9596Scientific Centre for Family Health and Human Reproduction Problems10.29413/ABS.2023-8.6.8actabiomedica-4495Research ArticleМИКРОБИОЛОГИЯ И ВИРУСОЛОГИЯMICROBIOLOGY AND VIRUSOLOGYГенетическая гетерогенность популяции Rickettsia helveticaGenetic heterogeneity of Rickettsia helvetica populationhttps://orcid.org/0000-0002-5930-5306РарВ. А.RarV. A.

Рар Вера Александровна – кандидат биологических наук, старший научный сотрудник лаборатории молекулярной микробиологии 

630090, г. Новосибирск, просп. Лаврентьева, 8

Vera A. Rar – Cand. Sc. (Biol.), Senior Research Officer at the Laboratory of Molecular Microbiology 

Lavrentyeva Ave. 8, Novosibirsk 630090

rarv@niboch.nsc.ruhttps://orcid.org/0000-0001-5604-1846ИголкинаЯ. П.IgolkinaYa. P.

Иголкина Яна Петровна – кандидат биологических наук, младший научный сотрудник молекулярной микробиологии 

630090, г. Новосибирск, просп. Лаврентьева, 8

Yana P. Igolkina – Cand. Sc. (Biol.), Junior Research Officer at the Laboratory of Molecular Microbiology 

Lavrentyeva Ave. 8, Novosibirsk 630090

igolkina@inbox.ruhttps://orcid.org/0000-0001-9088-3668ЯкименкоВ. В.YakimenkoV. V.

Якименко Валерий Викторович – доктор биологических наук, главный научный сотрудник, заведующий лабораторией арбовирусных инфекций отдела природно-очаговых вирусных инфекций 

644080, г. Омск, просп. Мира, 7

Valeriy V. Yakimenko – Dr. Sc. (Biol.), Chief Research Officer, Head of the Laboratory of Arbovirus Infections of the Department of Natural Focal Viral Infections 

Mira Ave. 7, Omsk 644080

yakimenko_vv@oniipi.orghttps://orcid.org/0000-0001-5613-5447ТикуновА. Ю.TikunovA. Yu.

Тикунов Артем Юрьевич – кандидат биологических наук, старший научный сотрудник, заведующий лабораторией противомикробных препаратов 

630090, г. Новосибирск, просп. Лаврентьева, 8

Artem Yu. Tikunov – Cand. Sc. (Biol.), Senior Research Officer, Head of the Laboratory of Antimicrobials 

Lavrentyeva Ave. 8, Novosibirsk 630090

arttik@ngs.ruhttps://orcid.org/0000-0002-3918-7832НикитинА. Я.NikitinA. Ya.

Никитин Алексей Яковлевич – доктор биологических наук, ведущий научный сотрудник зоолого-паразитологического отдела 

664047, г. Иркутск, ул. Трилиссера, 78

Aleksey Yu. Nikitin – Dr. Sc. (Biol.), Leading Research Officer at the Zoological and Parasitological Department 

Trilissera str. 78, Irkutsk 664047

nikitin_irk@mail.ruhttps://orcid.org/0009-0005-7077-1809ЕпихинаТ. И.EpikhinaT. I.

Епихина Тамара Ивановна – ведущий инженер лаборатории молекулярной микробиологии 

630090, г. Новосибирск, просп. Лаврентьева, 8

Tamara I. Epikhina – Lead Engineer at the Laboratory of Molecular Microbiology 

Lavrentyeva Ave. 8, Novosibirsk 630090

tiepikhina@gmail.comhttps://orcid.org/0000-0002-1687-8278ТикуноваН. В.TikunovaN. V.

Тикунова Нина Викторовна – доктор биологических наук, главный научный сотрудник, заведующий лабораторией молекулярной микробиологии 

630090, г. Новосибирск, просп. Лаврентьева, 8

Nina V. Tikunova – Dr. Sc. (Biol.), Chief Research Officer, Head of the Laboratory of Molecular Microbiology 

Lavrentyeva Ave. 8, Novosibirsk 630090

tikunova@niboch.nsc.ruФГБУН Институт химической биологии и фундаментальной медицины СО РАНInstitute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of SciencesФБУН «Омский научно-исследовательский институт природно-очаговых инфекций»Omsk Research Institute of Natural Focal InfectionsФКУЗ Иркутский научно-исследовательский противочумный институт Сибири и Дальнего Востока Федеральной службы по надзору в сфере защиты прав потребителей и благополучия человекаIrkutsk Antiplague Research Institute of Siberia and Far East of Rospotrebnadzor2023140120248691104Copyright © Рар В.А., Иголкина Я.П., Якименко В.В., Тикунов А.Ю., Никитин А.Я., Епихина Т.И., Тикунова Н.В., 20242024Рар В.А., Иголкина Я.П., Якименко В.В., Тикунов А.Ю., Никитин А.Я., Епихина Т.И., Тикунова Н.В.Rar V.A., Igolkina Y.P., Yakimenko V.V., Tikunov A.Y., Nikitin A.Y., Epikhina T.I., Tikunova N.V.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.actabiomedica.ru/jour/article/view/4495Обоснование

Обоснование. Генетическая вариабельность Rickettsia helvetica недостаточно изучена.

Цель исследования

Цель исследования. Изучить встречаемость и генетическую вариабельность R. helvetica в Ixodes spp., собранных в Сибири и на Дальнем Востоке.

Методы

Методы. На наличие риккетсий проанализированы клещи, снятые с грызунов в Омской области (n = 280) и собранные на флаг на островах Путятина и Русский в Приморском крае (n = 482). Для всех образцов риккетсий секвенированы фрагмента гена gltA, а для ряда образцов R. helvetica дополнительно секвенированы фрагменты  16S rRNA, ompA, ompB, sca4, htrA и groEL генов и 23S–5S межгенного спейсера.

Результаты

Результаты. Всего было выявлено четыре вида риккетсий. Из них R. helvetica обнаружена в 72,2 % Ixodes apronophorus и 18,8 % Ixodes trianguliceps из Омской области и в единичных Ixodes persulcatus из Омской области и с острова Путятина. Это первое выявление риккетсий в I. apronophorus. На основании проведённого филогенетического анализа последовательности R. helvetica из данной работы и из базы данных GenBank отнесены к четырём генетическим линиям. Линия  I включает европейские изоляты из Ixodes ricinus, изоляты из I. persulcatus из Западной Сибири и некоторые последовательности из I. apronophorus. Все последовательности R. helvetica из I. trianguliceps из Омской области и из I. persulcatus из Республики Коми, а также последовательность из I. apronophorus отнесены к линии II. Большинство последовательностей из I. apronophorus образуют линию III, а все последовательности R. helvetica из I. persulcatus с Дальнего Востока – линию IV.

Заключение

Заключение. Впервые показана генетическая гетерогенность популяции R.  helvetica. Известные изоляты R.  helvetica надёжно отнесены к четырём генетическим линиям, однако ассоциация различных линий с определённым видом клеща или с определённой территорией наблюдается не во всех случаях.

Background

Background. To date, the genetic variability of Rickettsia helvetica has not been sufficiently studied.

The aim

The aim. To study the prevalence and genetic variability of R. helvetica in Ixodes spp. collected in Western Siberia and the Russian Far East.

Materials and methods

Materials and methods. Ixodes  spp. collected from rodents in the Omsk province, Western Siberia (n = 280) and collected by flagging on Putyatin and Russky Islands in Primorsky Krai, Russian Far East (n = 482) were analyzed for the presence of Rickettsia spp. All positive samples were genotyped for the gltA gene fragment. For a number of R. helvetica samples, fragments of the 16S rRNA, ompA, ompB, sca4, htrA, and groEL genes and 23S–5S intergenic spacer were additionally sequenced.

Results

Results. Four Rickettsia species (R. helvetica, “Candidatus Rickettsia tarasevichiae”, “Candidatus Rickettsia uralica”, and “Candidatus Rickettsia mendelii”) were found. Of them, R. helvetica was identified in 72.2 % of Ixodes apronophorus and 18.8 % of  Ixodes trianguliceps from the Omsk province and in single Ixodes persulcatus from the Omsk province and Putyatin Island. This is the first finding of Rickettsia spp. in I. apronophorus. All known R. helvetica sequences from this study and the GenBank database belonged to four well supported monopheletic groups forming genetic lineages I–IV. Lineage I included European isolates from Ixodes ricinus, Western Siberian isolates from I. persulcatus, and some sequences from I. apronophorus. All R. helvetica sequences from I. trianguliceps from the Omsk province and I. persulcatus from  the  Komi Republic and one sequence from I.  apronophorus were assigned to  lineage  II. Most sequences from I.  apronophorus formed lineage  III; all known R. helvetica sequences from I. persulcatus from the Far East formed genetic lineage IV.

Conclusion

Conclusion. The genetic heterogeneity of R. helvetica population was first demonstrated. Known isolates of R. helvetica are reliably assigned to four genetic lineages, but not in all cases the association of different lineages with a specific tick species or specific territory was observed.

Ixodes apronophorusIxodes persulcatusIxodes triangulicepsRickettsia helveticaобласть симпатриигенетические линиифилогенетический анализIxodes apronophorusIxodes persulcatusIxodes triangulicepsRickettsia helveticasympatric areasgenetic lineagesphylogenetic analysisРабота выполнена при финансовой поддержке проекта Государственного задания ФГБУН Институт химической биологии и фундаментальной медицины СО РАН (№ 121031300043-8).ReferencesFournier PE, Grunnenberger F, Jaulhac B, Gastinger G, Raoult D. Evidence of Rickettsia helvetica infection in humans, eastern France. Emerg Infect Dis. 2000; 6(4): 389-392. doi: 10.3201/eid0604.000412Fournier PE, Grunnenberger F, Jaulhac B, Gastinger G, Raoult D. Evidence of Rickettsia helvetica infection in humans, eastern France. Emerg Infect Dis. 2000; 6(4): 389-392. doi: 10.3201/eid0604.000412Fournier PE, Allombert C, Supputamongkol Y, Caruso G, Brouqui P, Raoult D. Aneruptive fever associated with antibodies to Rickettsia helvetica in Europe and Thailand. J Clin Microbiol. 2004; 42(2): 816-818. doi: 10.1128/JCM.42.2.816-818.2004Fournier PE, Allombert C, Supputamongkol Y, Caruso G, Brouqui P, Raoult D. Aneruptive fever associated with antibodies to Rickettsia helvetica in Europe and Thailand. J Clin Microbiol. 2004; 42(2): 816-818. doi: 10.1128/JCM.42.2.816-818.2004Nilsson K, Lindquist O, Påhlson C. Association of Rickettsia helvetica with chronic perimyocarditis in sudden cardiac death. Lancet. 1999; 354(9185): 1169-1173. doi: 10.1016/S0140-6736(99)04093-3Nilsson K, Lindquist O, Påhlson C. Association of Rickettsia helvetica with chronic perimyocarditis in sudden cardiac death. Lancet. 1999; 354(9185): 1169-1173. doi: 10.1016/S0140-6736(99)04093-3Nilsson K, Påhlson C, Lukinius A, Eriksson L, Nilsson L, Lindquist O. Presence of Rickettsia helvetica in granulomatous tissue from patients with sarcoidosis. J Infect Dis. 2002; 185(8): 1128-1138. doi: 10.1086/339962Nilsson K, Påhlson C, Lukinius A, Eriksson L, Nilsson L, Lindquist O. Presence of Rickettsia helvetica in granulomatous tissue from patients with sarcoidosis. J Infect Dis. 2002; 185(8): 1128-1138. doi: 10.1086/339962Nilsson K, Elfving K, Pahlson C. Rickettsia helvetica in patient with meningitis, Sweden, 2006. Emerg Infect Dis. 2010; 16(3): 490-492. doi: 10.3201/eid1603.090184Nilsson K, Elfving K, Pahlson C. Rickettsia helvetica in patient with meningitis, Sweden, 2006. Emerg Infect Dis. 2010; 16(3): 490-492. doi: 10.3201/eid1603.090184Нефедова В.В., Коренберг Э.И., Ковалевский Ю.В., Горелова Н.Б., Воробьева Н.Н. Микроорганизмы порядка Rickettsiales у таежного клеща (Ixodes persulcatus Sch.) в Предуралье. Вестник РАМН. 2008; 7: 47-50.Nefedova VV, Korenberg EI, Kovalevskii YV, Vorobyeva NN. Microorganisms of the order Rickettsiales in taiga tick (Ixodes persulcatus Sch.) from the Pre-Ural region. Annals of the Russian Academy of Medical Sciences. 2008; 7: 47-50. (In Russ.).Silaghi C, Gilles J, Höhle M, Pradel I, Just FT, Fingerle V, et al. Prevalence of spotted fever group rickettsiae in Ixodes ricinus (Acari: Ixodidae) in southern Germany. J. Med. Entomol. 2008; 45: 948–955. doi: 10.1603/0022-2585(2008)45[948:posfgr]2.0.co;2Silaghi C, Gilles J, Höhle M, Pradel I, Just FT, Fingerle V, et al. Prevalence of spotted fever group rickettsiae in Ixodes ricinus (Acari: Ixodidae) in southern Germany. J. Med. Entomol. 2008; 45: 948–955. doi: 10.1603/0022-2585(2008)45[948:posfgr]2.0.co;2Stanko M, Derdáková M, Špitalská E, Kazimírová M. Ticks and their epidemiological role in Slovakia: From the past till present. Biologia (Bratisl). 2022; 77(6): 1575-1610. doi: 10.1007/s11756-021-00845-3Stanko M, Derdáková M, Špitalská E, Kazimírová M. Ticks and their epidemiological role in Slovakia: From the past till present. Biologia (Bratisl). 2022; 77(6): 1575-1610. doi: 10.1007/s11756-021-00845-3Kartashov MY, Glushkova LI, Mikryukova TP, Korabelnikov IV, Egorova YI, Tupota NL, et al. Detection of Rickettsia helvetica and Candidatus R. tarasevichiae DNA in Ixodes persulcatus ticks collected in Northeastern European Russia (Komi Republic). Ticks Tick Borne Dis. 2017; 8: 588-592. doi: 10.1016/j.ttbdis.2017.04.001Kartashov MY, Glushkova LI, Mikryukova TP, Korabelnikov IV, Egorova YI, Tupota NL, et al. Detection of Rickettsia helvetica and Candidatus R. tarasevichiae DNA in Ixodes persulcatus ticks collected in Northeastern European Russia (Komi Republic). Ticks Tick Borne Dis. 2017; 8: 588-592. doi: 10.1016/j.ttbdis.2017.04.001Shpynov SN, Fournier PE, Rudakov NV, Samoilenko IE, Reshetnikova TA, Yastrebov VK, et al. Molecular identification of a collection of spotted Fever group rickettsiae obtained from patients and ticks from Russia. Am J Trop Med Hyg. 2006; 74(3): 440-443.Shpynov SN, Fournier PE, Rudakov NV, Samoilenko IE, Reshetnikova TA, Yastrebov VK, et al. Molecular identification of a collection of spotted Fever group rickettsiae obtained from patients and ticks from Russia. Am J Trop Med Hyg. 2006; 74(3): 440-443.Rakov AV, Chekanova TA, Petremgvdlishvili K, Timonin AV, Valdokhina AV, Shirokostup SV, et al. High prevalence of Rickettsia raoultii found in Dermacentor ticks collected in Barnaul, Altai Krai, Western Siberia. Pathogens. 2023; 12(7): 914. doi: 10.3390/pathogens12070914Rakov AV, Chekanova TA, Petremgvdlishvili K, Timonin AV, Valdokhina AV, Shirokostup SV, et al. High prevalence of Rickettsia raoultii found in Dermacentor ticks collected in Barnaul, Altai Krai, Western Siberia. Pathogens. 2023; 12(7): 914. doi: 10.3390/pathogens12070914Rar V, Livanova N, Sabitova Y, Igolkina Y, Tkachev S, Tikunov A, et al. Ixodes persulcatus/pavlovskyi natural hybrids in Siberia: Occurrence in sympatric areas and infection by a wide range of tick-transmitted agents. Ticks Tick Borne Dis. 2019; 10(6): 101254. doi: 10.1016/j.ttbdis.2019.05.020Rar V, Livanova N, Sabitova Y, Igolkina Y, Tkachev S, Tikunov A, et al. Ixodes persulcatus/pavlovskyi natural hybrids in Siberia: Occurrence in sympatric areas and infection by a wide range of tick-transmitted agents. Ticks Tick Borne Dis. 2019; 10(6): 101254. doi: 10.1016/j.ttbdis.2019.05.020Пуховская Н.М., Рар В.А., Иванов Л.И., Высочина П.Н., Иголкина Я.П., Фоменко Н.В., и др. Выявление методом ПЦР возбудителей природно-очаговых инфекций, переносимых клещами, на полуострове Камчатка. Медицинская паразитология и паразитарные болезни. 2010; 4: 36-39.Pukhovskaia NM, Rar VA, Ivanov LI, Vysochina NP, Igolkina IaP, Fomenko NV, et al. PCR detection of the causative agents ofinfections transmitted by ticks on the Kamchatka Peninsula. Meditsinskaya parazitologiya i parazitarnye bolezni. 2010; 4: 36-39. (In Russ.).Igolkina Y, Bondarenko E, Rar V, Epikhina T, Vysochina N, Pukhovskaya N, et al. Genetic variability of Rickettsia spp. in Ixodes persulcatus ticks from continental and island areas of the Russian Far East. Ticks Tick Borne Dis. 2016; 7: 1284-1289. doi: 10.1016/j.ttbdis.2016.06.005Igolkina Y, Bondarenko E, Rar V, Epikhina T, Vysochina N, Pukhovskaya N, et al. Genetic variability of Rickettsia spp. in Ixodes persulcatus ticks from continental and island areas of the Russian Far East. Ticks Tick Borne Dis. 2016; 7: 1284-1289. doi: 10.1016/j.ttbdis.2016.06.005Малькова М.Г., Богданов И.И. Паразитофауна водяной полевки (Arvicola terrestris) и ее гнезд на юге Западной Сибири. Паразитология. 2004; 38: 33-45.Malkova MG, Bogdanov II Parasite fauna of the water vole Arvicola terrestris and its nests in south of Western Siberia. Parazitologiya. 2004; 38: 33-45. (In Russ.).Karimov AV, Korallo-Vinarskaya NP, Kuzmenko YF, Vinarski MV. Ixodes apronophorus Schulze (Acari: Ixodida: Ixodidae): Distribution, abundance, and diversity of its mammal hosts in West Siberia (Results of a 54-year long surveillance). Diversity. 2022; 14: 702. doi: 10.3390/d14090702Karimov AV, Korallo-Vinarskaya NP, Kuzmenko YF, Vinarski MV. Ixodes apronophorus Schulze (Acari: Ixodida: Ixodidae): Distribution, abundance, and diversity of its mammal hosts in West Siberia (Results of a 54-year long surveillance). Diversity. 2022; 14: 702. doi: 10.3390/d14090702Якименко В.В., Малькова М.Г., Шпынов С.Н. Иксодовые клещи Западной Сибири: фауна, экология, основные методы исследования. Омск; 2013.Yakimenko VV, Malkova MG, Shpynov SN. Ixodid ticks of the Western Siberia: Fauna, ecology, basic research methods. Omsk; 2013. (In Russ.).Nowak-Chmura M, Siuda K. Ticks of Poland. Review of contemporary issues and latest research. Ann Parasitol. 2012; 58(3): 125-55.Nowak-Chmura M, Siuda K. Ticks of Poland. Review of contemporary issues and latest research. Ann Parasitol. 2012; 58(3): 125-55.Igolkina YP, Rar VA, Yakimenko VV, Malkova MG, Tancev AK, Tikunov AY, et al. Genetic variability of Rickettsia spp. in Ixodes persulcatus/Ixodes trianguliceps sympatric areas from Western Siberia, Russia: Identification of a new Candidatus Rickettsia species. Infect Genet Evol. 2015; 34: 88-93. doi: 10.1016/j.meegid.2015.07.015Igolkina YP, Rar VA, Yakimenko VV, Malkova MG, Tancev AK, Tikunov AY, et al. Genetic variability of Rickettsia spp. in Ixodes persulcatus/Ixodes trianguliceps sympatric areas from Western Siberia, Russia: Identification of a new Candidatus Rickettsia species. Infect Genet Evol. 2015; 34: 88-93. doi: 10.1016/j.meegid.2015.07.015Rar V, Yakimenko V, Tikunov A, Vinarskaya N, Tancev A, Babkin I, et al. Genetic and morphological characterization of Ixodes apronophorus from Western Siberia, Russia. Ticks and Tick-Borne Diseases. 2020; 11(1): 101284. doi: 10.1016/j.ttbdis.2019.101284Rar V, Yakimenko V, Tikunov A, Vinarskaya N, Tancev A, Babkin I, et al. Genetic and morphological characterization of Ixodes apronophorus from Western Siberia, Russia. Ticks and Tick-Borne Diseases. 2020; 11(1): 101284. doi: 10.1016/j.ttbdis.2019.101284Филиппова Н.А. Иксодовые клещи подсемейства Ixodinae. Ленинград: Наука; 1977.Filippova NA. Ixodid ticks of the subfamily Ixodinae. Leningrad: Nauka; 1977. (In Russ.).Fournier PE, Roux V, Raoult D. Phylogenetic analysis of spotted fever group rickettsiae by study of the outer surface protein rOmpA. Int J Syst Bacteriol. 1998; 48 (3): 839-849. doi: 10.1099/00207713-48-3-839Fournier PE, Roux V, Raoult D. Phylogenetic analysis of spotted fever group rickettsiae by study of the outer surface protein rOmpA. Int J Syst Bacteriol. 1998; 48 (3): 839-849. doi: 10.1099/00207713-48-3-839Roux V, Raoult D. Phylogenetic analysis of members of the genus Rickettsia using the gene encoding the outer-membrane protein rOmpB (ompB). Int J Syst Evol Microbiol. 2000; 50: 1449-1455. doi: 10.1099/00207713-50-4-1449Roux V, Raoult D. Phylogenetic analysis of members of the genus Rickettsia using the gene encoding the outer-membrane protein rOmpB (ompB). Int J Syst Evol Microbiol. 2000; 50: 1449-1455. doi: 10.1099/00207713-50-4-1449Sekeyova Z, Roux V, Raoult D. Phylogeny of Rickettsia spp. inferred by comparing sequences of ‘gene D’, which encodes an intracytoplasmic protein. Int J Syst Evol Microbiol. 2001; 51(4): 1353-1360. doi: 10.1099/00207713-51-4-1353Sekeyova Z, Roux V, Raoult D. Phylogeny of Rickettsia spp. inferred by comparing sequences of ‘gene D’, which encodes an intracytoplasmic protein. Int J Syst Evol Microbiol. 2001; 51(4): 1353-1360. doi: 10.1099/00207713-51-4-1353Matsumoto K, Inokuma H. Identification of spotted fever group Rickettsia species by polymerase chain reaction-restriction fragment length polymorphism analysis of the sca4 gene. Vector Borne Zoonotic Dis. 2009; 9(6): 747-749. doi: 10.1089/vbz.2008.0098Matsumoto K, Inokuma H. Identification of spotted fever group Rickettsia species by polymerase chain reaction-restriction fragment length polymorphism analysis of the sca4 gene. Vector Borne Zoonotic Dis. 2009; 9(6): 747-749. doi: 10.1089/vbz.2008.0098Labruna MB, McBride JW, Bouyer DH, Camargo LM, Camargo EP, Walker DH. Molecular evidence for a spotted fever group Rickettsia species in the tick Amblyomma longirostre in Brazil. J Med Entomol. 2004; 41(3): 533-537. doi: 10.1603/0022-2585-41.3.533Labruna MB, McBride JW, Bouyer DH, Camargo LM, Camargo EP, Walker DH. Molecular evidence for a spotted fever group Rickettsia species in the tick Amblyomma longirostre in Brazil. J Med Entomol. 2004; 41(3): 533-537. doi: 10.1603/0022-2585-41.3.533Jado I, Escudero R, Gil H, Jiménez-Alonso MI, Sousa R, García-Pérez AL, et al. Molecular method for identification of Rickettsia species in clinical and environmental samples. J Clin Microbiol. 2006; 44(12): 4572-4576. doi: 10.1128/JCM.01227-06Jado I, Escudero R, Gil H, Jiménez-Alonso MI, Sousa R, García-Pérez AL, et al. Molecular method for identification of Rickettsia species in clinical and environmental samples. J Clin Microbiol. 2006; 44(12): 4572-4576. doi: 10.1128/JCM.01227-06Shao JW, Zhang XL, Li WJ, Huang HL, Yan J. Distribution and molecular characterization of rickettsiae in ticks in Harbin area of Northeastern China. PLoS Negl Trop Dis. 2020; 14(6): e0008342. doi: 10.1371/journal.pntd.0008342Shao JW, Zhang XL, Li WJ, Huang HL, Yan J. Distribution and molecular characterization of rickettsiae in ticks in Harbin area of Northeastern China. PLoS Negl Trop Dis. 2020; 14(6): e0008342. doi: 10.1371/journal.pntd.0008342National Library of Medicine. Basic Local Alignment Search Tool. URL: http://www.ncbi.nlm.nih.gov/BLAST [date of access: 05.09.2023].National Library of Medicine. Basic Local Alignment Search Tool. URL: http://www.ncbi.nlm.nih.gov/BLAST [date of access: 05.09.2023].Molecular Evolutionary Genetics Analysis. URL: http://www.megasoftware.net/manual.html [date of access: 05.09.2023].Molecular Evolutionary Genetics Analysis. URL: http://www.megasoftware.net/manual.html [date of access: 05.09.2023].Kumar Lab – Laboratory of Sudhir Kumar. URL: http://www.kumarlab.net/publications [date of access: 05.09.2023].Kumar Lab – Laboratory of Sudhir Kumar. URL: http://www.kumarlab.net/publications [date of access: 05.09.2023].Parola P, Paddock CD, Socolovschi C, Labruna MB, Mediannikov O, Kernif T, et al. Update on tick-borne rickettsioses around the world: A geographic approach. Clin Microbiol Rev. 2013; 26(4): 657-702. doi: 10.1128/CMR.00032-13Parola P, Paddock CD, Socolovschi C, Labruna MB, Mediannikov O, Kernif T, et al. Update on tick-borne rickettsioses around the world: A geographic approach. Clin Microbiol Rev. 2013; 26(4): 657-702. doi: 10.1128/CMR.00032-13Moraes-Filho J, Costa FB, Gerardi M, Soares HS, Labruna MB. Rickettsia rickettsii co-feeding transmission among Amblyomma aureolatum ticks. Emerg Infect Dis. 2018; 24(11): 2041-2048. doi: 10.3201/eid2411.180451Moraes-Filho J, Costa FB, Gerardi M, Soares HS, Labruna MB. Rickettsia rickettsii co-feeding transmission among Amblyomma aureolatum ticks. Emerg Infect Dis. 2018; 24(11): 2041-2048. doi: 10.3201/eid2411.180451

The authors declare that there are no conflicts of interest present.